<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="https://cdn.jsdelivr.net/npm/vue@2.6.14/dist/vue.js"></script>
</head>

<body>
    <div id="root">
        <h1>学生信息</h1>
        <button @click="student.age++">年龄+1</button>
        <button @click="addSex"> 添加性别属性 </button>
        <button @click="student.sex='未知'"> 修改性别属性 </button>
        <button @click="addFriend">列表首位添加一个朋友</button>
        <button @click="updateFirstFriendName">修改第一个朋友的名字：张三</button>
        <button @click="hobby">添加一个爱好</button>
        <button @click="updateHobby">修改第一个爱好：开车</button>
        <button @click="removeSmoke">过滤爱好中抽烟</button>
        <h3>姓名：{{student.name}}</h3>
        <h3>年龄：{{student.age}}</h3>
        <h3 v-if="student.sex">性别：{{student.sex}}</h3>
        <h3>爱好：</h3>
        <ul>
            <li v-for="(item,index) in student.hobby" :key="index">
                {{item}}
            </li>
        </ul>
        <h3>朋友们</h3>
        <ul>
            <li v-for="(f,index) in student.friends" :key="index">
                {{f.name}}--{{f.age}}
            </li>
        </ul>
    </div>
    <script>
        const vm = new Vue({
            el: "#root",
            data: {
                student: {
                    name: 'tom',
                    age: 18,
                    hobby: ['抽烟', '喝酒', '烫头'],
                    friends: [{
                            name: 'jeny',
                            age: 30
                        },
                        {
                            name: 'tony',
                            age: 36
                        },
                    ]
                },

            },
            methods: {
                addSex() {
                    Vue.set(this.student, 'sex', '男')
                    //this.$set(this.student,'sex','男')
                },
                addFriend() {
                    this.student.friends.unshift({
                        name: 'jack',
                        age: 40
                    })
                },
                updateFirstFriendName() {
                    this.student.friends[0].name = '张三'
                },
                hobby() {
                    this.student.hobby.push('学习')
                },
                updateHobby() {
                    this.student.hobby.splice(0, 1, '开车')
                },
                removeSmoke() {
                    this.student.hobby = this.student.hobby.filter(k => {
                        return k != '抽烟'
                    })
                }
            },
        })
    </script>
</body>

</html>